This invention relates to a laminated structure comprising at least two layers of ceramic material, the properties of the material in one layer being distinctly different from those of the material in the other layer. The laminated ceramic structure is particularly useful in providing impact resistance, especially resistance to projectile penetration. It may also prove useful where severe erosive conditions are encountered, as in such diverse items as material mixers and exhaust components on jet engines.
It has been customary to employ metal tile or cladding as protection against such adverse influences as projectile penetration or erosive action by the environment. The need for an ever-increasing degree of resistance has been met, but at the expense of severe weight problem. Accordingly, it has recently been proposed to employ a glass-ceramic material having a high thermal coefficient of expansion, the glass-ceramic being used either alone or bonded to a steel backing plate.
Laminated glass articles are also known. Thus, the safety glass used in auto windshields is composed of glass sheets joined with a thin interlayer of plastic. The laminated glass may be made thicker and strengthened in making bullet-proof glass.
While these structures have met some needs, there has remained a continued interest in obtaining greater resistance capability per unit weight.